GPM effect on BTU 1

[mbsell]

Hello Members. Does anyone have a formula that I can use to calculate BTU at varying GPM's?

For example:

A piece of heating equipment generates 90,000 Btu @ 9.0 gpm of hot water (Based on 200 EWT, 180 LWT, 60 EAT). What would the BTU output be at 5.0 GPM?

Thank you for your help.
MB

 

[btrueblood]

First, your units of Btu are, I assume, really Btu/hr.

Use the following two equations:

1. "Tons" = (GPM * Delta-T)/24

2. Tons * 12000 = Btu/hr

So, (9 gpm * 20 deg. F) / 24 = 7.5 tons = 90000 Btu/hr

(5 gpm * 20 deg. F)/ 24 = 4.2 tons = 50000 Btu/hr

That, of course, assumes that the 20 deg. delta-T stays constant (it may go up, but if you aren't using a good pressure-independent control valve to modulate the flow it may very well go down).

 

[Yorkman]

mbsell,
A relatively simple formula for finding the sensible heat in BTU/HR for water, used in many heating calculations is: BTU/Hr = 500 x GPM x ?T
The 500 comes from: 8.33 x 1 x60 = 499.89 or(500)
8.33lbs/gal
1.0 = specific heat of water
60 minutes/Hr
?T = E.W.T. - L.W.T. for heating or L.W.T.-E.W.T. for
cooling
If the liquid you are working with is somthing other than water then you will need to adjust the 500 factor by using the correct specific heat value. Goodluck

I'm not a real engineer, but I play one on T.V.
A.J. Gest, York Int.

 

[Yorkman]

Dont know why but my delta trangles came out looking like question marks but you get the general idea ??

I'm not a real engineer, but I play one on T.V.
A.J. Gest, York Int.

 

[unclesyd]

Try this Δ Enclose this expression in square brackets. Note the capitol D. Check it out in Preview Post

[Δ][Δ][Δ][Δ][Δ]

Go to Preview Post and Check the second page for the Mathematical Notation

 

[Yorkman]

[&D]

I'm not a real engineer, but I play one on T.V.
A.J. Gest, York Int.

 

[Yorkman]

[&Delta]

I'm not a real engineer, but I play one on T.V.
A.J. Gest, York Int.

 

[Yorkman]

[Δ]

I'm not a real engineer, but I play one on T.V.
A.J. Gest, York Int.